BIO-150 Final Exam Study Guide

Introduction to Human Body

  • Anatomy: The study of the structure of body parts and their relationships to one another.
  • Physiology: The study of how body parts function.
  • Levels of Structural Organization:
    • Chemicals: Atoms and molecules essential for life (e.g., carbon, hydrogen, water, proteins).
    • Cells: The basic structural and functional units of an organism (e.g., muscle cell, nerve cell).
    • Tissues: Groups of similar cells that perform a specific function (e.g., muscle tissue, nervous tissue).
    • Organs: Structures composed of two or more different types of tissues that perform specific functions (e.g., heart, brain).
    • Organ Systems: Groups of organs that work together to accomplish a common purpose (e.g., cardiovascular system, digestive system).
    • Organism: All the levels working together to form a complete living being.
  • Eleven Body Systems:
    • Integumentary System: Skin, hair, nails, sweat glands, and oil glands. Protects the body, regulates temperature, eliminates waste, synthesizes vitamin D.
    • Skeletal System: Bones, cartilage, ligaments, and joints. Supports and protects the body, provides framework for muscles, produces blood cells, stores minerals.
    • Muscular System: Skeletal, smooth, and cardiac muscles. Movement, posture, heat production.
    • Nervous System: Brain, spinal cord, nerves, and sensory organs. Regulates body activities through nerve impulses, interprets sensory input.
    • Endocrine System: Glands (e.g., pituitary, thyroid, adrenal) that produce hormones. Regulates body activities by releasing hormones into the blood.
    • Cardiovascular System: Heart, blood vessels, and blood. Pumps blood to transport oxygen, nutrients, hormones, and waste products.
    • Lymphatic System/Immunity: Lymphatic fluid, vessels, spleen, thymus, lymph nodes, tonsils. Returns fluid to blood, involved in immunity.
    • Respiratory System: Lungs and air passages (e.g., pharynx, larynx, trachea, bronchi). Exchanges oxygen and carbon dioxide between blood and air.
    • Digestive System: Organs of the gastrointestinal tract (e.g., mouth, esophagus, stomach, intestines), plus accessory organs (teeth, tongue, salivary glands, liver, gallbladder, pancreas). Breaks down food, absorbs nutrients, eliminates solid waste.
    • Urinary System: Kidneys, ureters, urinary bladder, and urethra. Filters blood, produces and excretes urine, regulates fluid and electrolyte balance.
    • Reproductive System: Gonads (testes and ovaries) and associated organs. Produces gametes (sperm and oocytes) and hormones; females also nourish and deliver the fetus.

Homeostasis and Feedback Systems

  • Homeostasis: The maintenance of relatively stable internal conditions in the body regardless of changes in the external environment. Its importance lies in ensuring optimal conditions for cell function and survival.
  • Feedback Systems:
    • Negative feedback: Reverses the original stimulus to maintain a variable within a normal range. It is the most common type of feedback mechanism in the body.
    • Example of negative feedback maintaining homeostasis (body temperature regulation):
      • Stimulus: Body temperature rises above normal (37^ ext{o} ext{C}) due to external heat.
      • Receptor: Thermoreceptors in the skin and hypothalamus detect the increase in temperature.
      • Control Center: Hypothalamus (brain) receives input from receptors and processes the information.
      • Effector: Sweat glands activate, increasing sweat production to cool the body; blood vessels in the skin dilate, increasing heat loss from the surface. The body temperature decreases, returning to normal.
    • Positive feedback: Strengthens or reinforces a change in a controlled variable. It is less common and typically involved in events that need to be completed quickly.
    • Example of positive feedback (childbirth):
      • Stimulus: Uterine contractions begin.
      • Purpose: To intensify the contractions until the baby is delivered, after which the feedback loop terminates.

Anatomical Terminology

  • visceral: Pertaining to the internal organs or the covering of an organ (e.g., visceral pleura covers the surface of the lungs).
  • parietal: Pertaining to the wall of a cavity (e.g., parietal pleura lines the thoracic cavity).
  • afferent: Carrying toward a center (e.g., afferent neurons carry sensory information to the brain).
  • efferent: Carrying away from a center (e.g., efferent neurons carry motor commands from the brain).
  • frontal/coronal plane: A vertical plane that divides the body or an organ into anterior (front) and posterior (back) portions.
  • transverse plane: A horizontal plane that divides the body or an organ into superior (upper) and inferior (lower) portions.
  • pleural cavity: The space between the parietal and visceral pleurae, surrounding the lungs.
  • pericardial cavity: The space between the parietal and visceral pericardium, surrounding the heart.
  • Anatomical terms for limbs:
    • brachial: Pertaining to the arm (upper arm).
    • femoral: Pertaining to the thigh.
    • carpal: Pertaining to the wrist.
    • tarsal: Pertaining to the ankle.
    • calcaneal: Pertaining to the heel.

Chemistry and Elements

  • Major Elements:
    • Oxygen (O): Part of water and many organic molecules; essential for respiration.
    • Hydrogen (H): Part of water, acids, bases, and all organic molecules.
    • Nitrogen (N): Component of proteins and nucleic acids.
    • Carbon (C): Backbone of all organic molecules.
    • Calcium (Ca): Bone and teeth structure, muscle contraction, blood clotting, nerve function.
    • Phosphorus (P): Component of nucleic acids (DNA, RNA), ATP, and bones and teeth.
  • Structure of an Atom:
    • Protons: Positively charged subatomic particles located in the nucleus. Determine the atomic number.
    • Neutrons: Neutrally charged subatomic particles located in the nucleus. Contribute to the mass number.
    • Electrons: Negatively charged subatomic particles that orbit the nucleus in shells. Involved in chemical bonding.
    • Atomic number: The number of protons in the nucleus of an atom. Defines the element.
    • Mass number: The total number of protons and neutrons in an atom's nucleus.
  • Ions and Molecules:
    • Ions: An atom or molecule that has gained or lost one or more electrons, resulting in a net electrical charge.
    • Cations: Positively charged ions (lose electrons).
    • Anions: Negatively charged ions (gain electrons).
    • Molecules: Two or more atoms held together by chemical bonds.
    • Compounds: Molecules that contain atoms of at least two different elements.

Chemical Bonds

  • Types of Bonds:
    • Covalent bonds: Formed when atoms share electrons.
    • Non-polar covalent: Equal sharing of electrons between atoms (e.g., ext{O}_ ext{2}).
    • Polar covalent: Unequal sharing of electrons, creating slight positive and negative poles (e.g., ext{H}_ ext{2} ext{O}).
    • Ionic bonds: Formed when one atom transfers electrons to another, resulting in oppositely charged ions that attract each other (e.g., NaCl).
    • Hydrogen bonds: Weak attractions between a partially positive hydrogen atom in one polar molecule and a partially negative atom (usually oxygen or nitrogen) in another polar molecule.
  • Chemical Reactions:
    • Metabolism: All chemical reactions that occur in the body, including catabolism (breakdown) and anabolism (synthesis).
    • Synthesis reactions (Anabolism): Two or more atoms/molecules combine to form a larger molecule ( ext{A} + ext{B} \rightarrow ext{AB}).
    • Decomposition reactions (Catabolism): A larger molecule is broken down into smaller atoms/molecules ( ext{AB} \rightarrow ext{A} + ext{B}).
    • Exchange reactions: Parts of two different molecules exchange places ( ext{AB} + ext{CD} \rightarrow ext{AD} + ext{CB}).
    • Reversible reactions: Reactions that can proceed in both directions, often indicated by a double arrow ( ext{A} + ext{B}
      ightleftharpoons ext{AB}).
  • Energy Transfer:
    • Potential energy: Stored energy, capable of doing work but not actively doing so (e.g., chemical energy in bonds).
    • Kinetic energy: Energy of motion, actively doing work (e.g., moving muscles).
    • Activation energy: The minimum amount of energy required for a chemical reaction to occur.
    • Role of catalysts (enzymes): Substances that speed up chemical reactions by lowering the activation energy without being consumed in the reaction.

Inorganic vs. Organic Compounds

  • Differences and examples:
    • Inorganic compounds: Generally lack carbon and are structurally simple (e.g., water ( ext{H}_ ext{2} ext{O}), salts, acids, bases).
    • Organic compounds: Always contain carbon, usually hydrogen, and always have covalent bonds. They are typically large, complex molecules (e.g., carbohydrates, proteins, lipids, nucleic acids).
  • Water's Polar Characteristic: Due to its bent shape and the electronegativity difference between oxygen and hydrogen, water molecules have a slight negative charge near the oxygen and slight positive charges near the hydrogens. This polarity makes water an excellent solvent for other polar or charged substances, like NaCl, by forming hydration shells around the ions.

Acids, Bases, Buffers

  • Acids: Substances that release hydrogen ions ( ext{H}^+) when dissolved in water, lowering the pH (e.g., HCl).
  • Bases: Substances that accept hydrogen ions or release hydroxide ions ( ext{OH}^-) when dissolved in water, raising the pH (e.g., NaOH).
  • Salts: Ionic compounds formed from the reaction of an acid and a base (e.g., NaCl).
  • Role of buffers in homeostasis: Buffers are weak acids or bases that can absorb excess H^+ or ext{OH}^- ions, thereby resisting large changes in pH and helping to maintain the body's pH within a narrow, life-sustaining range.

Organic Molecules in the Body

  • Four Major Groups:
    • Carbohydrates
    • Proteins
    • Lipids
    • Nucleic acids
  • Carbohydrates:
    • Monosaccharides: Simple sugars, such as glucose and fructose, the basic building blocks of carbohydrates.
    • Disaccharides: Two monosaccharides linked together, such as sucrose (table sugar).
    • Polysaccharides: Long chains of many monosaccharides, such as starch, glycogen (storage in animals), and cellulose.
    • Functions of carbohydrates: Primary source of energy for the body, structural component in some cells.
  • Proteins & Lipids:
    • Proteins:
    • Functions: Structural support (collagen, keratin), transport (hemoglobin), enzymes (catalyze reactions), movement (actin, myosin), communication (hormones, receptors), defense (antibodies).
    • Structure: Polymers of amino acids linked by peptide bonds. The specific sequence of amino acids (primary structure) dictates the protein's overall 3D shape and function.
    • Lipids:
    • Functions: Long-term energy storage, insulation, protection of organs, structural component of cell membranes (phospholipids), hormones (steroids).
    • Structures:
      • Triglycerides: Composed of a glycerol backbone and three fatty acid chains; main form of fat storage.
      • Phospholipids: Modified triglycerides with a phosphate group replacing one fatty acid chain, making them amphipathic (having both hydrophilic and hydrophobic parts); key component of cell membranes.

Nucleic Acids

  • Types:
    • DNA (deoxyribonucleic acid): Contains the genetic instructions for the development and function of all known living organisms.
    • RNA (ribonucleic acid): Involved in various roles in molecular biology, including coding, decoding, regulation, and expression of genes.
  • Base-pairing rules: In DNA, adenine (A) always pairs with thymine (T), and guanine (G) always pairs with cytosine (C). In RNA, adenine (A) pairs with uracil (U) instead of thymine.
  • Explanation of DNA's role in genetic information: DNA carries the hereditary information, organized into genes, which are segments that contain codes for specific proteins or functional RNA molecules. This genetic information is essential for controlling all cellular activities and passing traits from one generation to the next.

ATP Structure and Function

  • Structure: Adenosine triphosphate (ATP) consists of an adenine base, a ribose sugar, and three phosphate groups attached in series.
  • Energy bonds: The bonds connecting the second and third phosphate groups, and the first and second phosphate groups, are high-energy phosphate bonds. When these bonds are broken, a significant amount of energy is released.
  • ATP cycle: ATP continually cycles between ATP and ADP (adenosine diphosphate).
    • Retaining energy: Energy from the breakdown of glucose and other organic molecules is used to add a phosphate group to ADP, forming ATP (phosphorylation).
    • Releasing energy: When a cell requires energy, the terminal phosphate bond of ATP is broken, releasing energy and forming ADP + inorganic phosphate ( ext{ATP} \rightarrow ext{ADP} + ext{P}_ ext{i} + ext{Energy}). ADP can then be re-phosphorylated back to ATP during cellular respiration to store energy again.

Cell Anatomy and Function

  • Major cell areas and their functions:
    • Mitochondria: "Powerhouses" of the cell; generate most of the cell's supply of ATP through cellular respiration.
    • Ribosomes: Sites of protein synthesis, composed of ribosomal RNA and proteins.
    • Endoplasmic Reticulum (ER):
    • Rough ER: Studded with ribosomes; involved in the synthesis of proteins destined for secretion or insertion into membranes.
    • Smooth ER: Lacks ribosomes; involved in lipid synthesis, detoxification of drugs and poisons, and calcium storage.
    • Golgi apparatus: Modifies, sorts, and packages proteins and lipids into vesicles for secretion or delivery to other organelles.
    • Lysosomes: Contain digestive enzymes to break down waste materials and cellular debris.
    • Peroxisomes: Contain enzymes that detoxify harmful substances and perform lipid metabolism.
    • Nucleus: Contains the cell's genetic material (DNA), controls cell growth and reproduction.
    • Cytoplasm: The entire contents within the cell membrane, excluding the nucleus. Consists of cytosol (the jelly-like substance) and organelles.
  • Protein synthesis: The process by which cells make proteins.
    • Transcription: The process of copying genetic information from DNA into an RNA molecule (specifically messenger RNA, mRNA) in the nucleus.
    • Translation: The process where ribosomes read the mRNA sequence and synthesize a protein according to the genetic code, occurring in the cytoplasm.
  • Differences:
    • Somatic cells: All body cells except the gametes (sperm and egg cells). They are diploid.
    • Reproductive cells (gametes): Sperm and egg cells. They are haploid.
    • Diploid cells: Cells containing two sets of chromosomes, one from each parent (2n). Ex: Somatic cells (e.g., 46 chromosomes in humans).
    • Haploid cells: Cells containing a single set of chromosomes (n). Ex: Gametes (e.g., 23 chromosomes in humans).

Plasma Membrane Structure

  • Fluid-Mosaic Model: Describes the structure of the plasma membrane as a dynamic, flexible lipid bilayer with a mosaic of various proteins embedded in or associated with it. The fluid nature allows components to move laterally, and the mosaic of proteins performs diverse functions.
    • Membrane components and their functions:
    • Phospholipid bilayer: Forms the basic framework, creating a semi-permeable barrier.
    • Cholesterol: Provides stability and regulates fluidity.
    • Integral proteins: Embedded within the lipid bilayer, involved in transport, signaling, and cell adhesion.
    • Peripheral proteins: Loosely attached to the surface; involved in cell recognition, enzymes, and structural support.
    • Glycocalyx (carbohydrate chains): Cell recognition, adhesion, and protection.
  • Types of transport across the membrane:
    • Passive transport: Movement of substances across the membrane without requiring cellular energy (ATP).
    • Examples: Diffusion (simple and facilitated), osmosis, filtration.
    • Active transport: Movement of substances across the membrane against their concentration gradient, requiring cellular energy (ATP).
    • Examples: Primary active transport (using ATP directly, e.g., sodium-potassium pump), secondary active transport, vesicular transport (endocytosis, exocytosis).
  • Solutions and Cell Response:
    • Hypertonic solution: A solution with a higher concentration of solutes and a lower concentration of water than the cell's cytoplasm. In a hypertonic solution, water leaves the red blood cell, causing it to shrink or crenate.
    • Hypotonic solution: A solution with a lower concentration of solutes and a higher concentration of water than the cell's cytoplasm. In a hypotonic solution, water enters the red blood cell, causing it to swell and potentially burst (hemolysis).
    • Isotonic solution: A solution with the same concentration of solutes and water as the cell's cytoplasm. In an isotonic solution, red blood cells maintain their normal shape as there is no net movement of water.

Histology

  • Definition: The microscopic study of tissues.
  • Four major tissue types:
    • Epithelial tissue: Covers body surfaces, lines hollow organs, body cavities, and ducts, and forms glands.
    • Connective tissue: Protects and supports the body and its organs, binds organs together, stores energy reserves as fat, and provides immunity.
    • Muscular tissue: Generates physical force needed to make body structures move, maintain posture, and generate heat.
    • Nervous tissue: Detects changes inside and outside the body and responds by generating nerve impulses that activate muscular contractions and glandular secretions.
  • Functions of epithelial tissue:
    • Protection
    • Secretion
    • Absorption
    • Excretion
    • Filtration
    • Sensory reception
  • Types (covering/lining vs. glandular):
    • Covering and lining epithelium: Forms the outer covering of the skin and some internal organs, and lines blood vessels, ducts, body cavities, and the interior of the respiratory, digestive, urinary, and reproductive systems.
    • Glandular epithelium: Forms glands that produce and secrete substances.
  • Examples of membranes and their functions:
    • Serous membranes (serosa): Line closed body cavities (e.g., pleural, pericardial, peritoneal cavities) and cover the organs within them. They secrete serous fluid to reduce friction between organs and cavity walls.
    • Mucous membranes (mucosa): Line body cavities that open to the exterior (e.g., digestive, respiratory, urinary, reproductive tracts). They secrete mucus to lubricate, moisten, and protect the lining.

Integumentary System

  • Functions: Protection (chemical, physical, biological barrier), body temperature regulation, cutaneous sensation, metabolic functions (vitamin D synthesis), blood reservoir, excretion.
  • Structure of the skin: Composed of two main layers: the epidermis (superficial) and the dermis (deep), resting on the hypodermis (subcutaneous tissue which is not part of the skin).
  • Layers of skin and accessory structures:
    • Epidermis: Outermost protective layer, composed of keratinized stratified squamous epithelium.
    • Dermis: Deeper layer of connective tissue, containing blood vessels, nerves, hair follicles, and glands.
    • Accessory structures: Hair, nails, sweat glands, sebaceous (oil) glands.
  • Role of keratin and keratinization process:
    • Keratin: A tough, fibrous protein that gives epidermis its protective properties.
    • Keratinization: The process by which cells in the epidermis (keratinocytes) fill with keratin, die, and form tough, protective layers. This process provides a durable, water-resistant barrier.

Skeletal System

  • Functions of bone and skeletal system: Support, protection, movement (leverage for muscles), mineral storage (especially calcium and phosphate), blood cell formation (hematopoiesis in red bone marrow), triglyceride storage (yellow bone marrow).
  • Structure of compact and spongy bone:
    • Compact bone: Dense, outer layer of bone. Provides strength and protection. Organized into osteons.
    • Spongy bone (cancellous bone): Inner layer, less dense. Consists of a network of bony spikes called trabeculae, which provides strength without excessive weight. Contains red bone marrow.
  • Bone cells and their functions:
    • Osteocytes: Mature bone cells, maintain the bone matrix.
    • Osteoblasts: Bone-forming cells, synthesize and secrete new bone matrix (osteoid).
    • Osteoclasts: Bone-resorbing cells, break down bone matrix to release minerals.
  • Role of bones in calcium homeostasis; hormonal regulation by PTH and calcitonin:
    • Bones act as a reservoir for calcium. Blood calcium levels are tightly regulated to ensure proper nerve and muscle function.
    • Parathyroid hormone (PTH): Released by parathyroid glands when blood Ca^{2+} levels are low. PTH stimulates osteoclasts to resorb bone, releasing Ca^{2+} into the blood, and increases Ca^{2+} reabsorption in kidneys.
    • Calcitonin: Released by the thyroid gland when blood Ca^{2+} levels are high. Calcitonin inhibits osteoclast activity and promotes Ca^{2+} uptake by bones, lowering blood Ca^{2+} levels.
  • Total number of bones in the human body: Typically 206 bones in adults.
  • Axial vs. appendicular skeleton distinctions:
    • Axial skeleton: Forms the long axis of the body. Includes the skull, vertebral column, and thoracic cage (ribs and sternum). Its primary function is protection of vital organs and support.
    • Appendicular skeleton: Consists of the bones